The present invention relates to a novel fungicidal composition comprising a 2-aminothiazolecarboxamide derivative, N-(xcex1-cyano-2-thenyl)-4-ethyl-2-(ethylamino)-5-thiazolecarboxamide (ISO proposed name: ethaboxam) of the formula: 
and as an adjuvant a suitable nonionic surfactant.
A compound of formula (I), ethaboxam, was already described as a fungicidal compound for crop protection in Korean Patent No. 124,552 (Korean patent application No. 94-19960). Further, ethaboxam-containing formulations, e.g. wettable powder (trade name: Guardian; marketed by Misung Ltd.) were known.
An adjuvant is a non-pesticidal compound for enhancing a total activity of a pesticide, differently from a co-formulant which controls physical properties of active ingredients to facilitate their handling. Presence of the adjuvant in a pesticidal formulation increases a total quantity of active ingredients which can be contacted with and/or penetrated into a target plant thereby to enhance the activity of pesticide and to remarkably reduce the quantity of active ingredients which needs to be applied. Currently, Envirornental Protection Agency in the U.S.A. and Ministry of Agriculture, Fisheries and Food in the United Kingdom are recognizing the employment of the adjuvant as a major tool for obtaining desired activity of novel active ingredients.
An adjuvant is widely used in leading advanced countries such as the U.S.A. and European countries and conventionally, is manufactured and marketed as a separate package for use as a tank-mix formulation in spraying herbicides. Recently, its application is also extended to fungicides, insecticides, growth regulators and fertilizers. However, the adjuvant for use as the tank-mix formulation is manufactured as a separate package and thus, its production and transportation costs are unavoidably increased and particularly, strict experimental data are required for its registration. Therefore, its development takes a long time and requires enormous expenses.
Recently, several leading agrochemical manufacturers are likely to formulate an adjuvant in combination with active ingredients in one package thereby to facilitate mixing, transportation and particularly, registration of products. A formulation containing the adjuvant in combination with the active ingredients in one package is referred to as a premixed one-pack formulation, a contrary concept to a tank-mixed formulation. An example of the premixed one-pack formulations is a round-up formulation containing as the adjuvant tallow amine and as the herbicidal compound glyphosate in one package.
Conventionally, an adjuvant for fungicides is added to a spray liquid when applied and a product containing 75-95% of a mineral oil and 5-25% of a surfactant is widely used. This adjuvant increases the fungicidal activity by improving the retention of active ingredients to plants rather than by increasing foliar penetration of active ingredients. However, such mineral oil-containing product may cause injury to plants and environmental contamination due to its low biodegradability.
Recently, in order to increase the efficacy of high-activity penetrative fungicides, it was suggested that non-ionic surfactants such as sorbitan esters of fatty acids, polyoxyethylene alkyl ethers, polyoxyethylene sorbitan esters, polyoxyethylene alkyl phenol ethers, polyoxyethylene amides be incorporated into the fungicides (see U.S. Pat. No. 5,905,072). Examples of fungicides which can be employed are as follows: triazoles, e.g. tetraconazole, triadimefon, triadimenol, propiconazole, penconazole, hexaconazole, cyproconazole, flusilazole, etc.; imidazoles, e.g. prochloraz, imazalil, etc.; morpholines, e.g. fenpropimorph, tridemorph, etc.; dicarboxyimides, e.g. iprodione, vinclozolin, etc.; piperidines, e.g. fenprodipin, etc.; acyl alanines, e.g. metalaxyl, benalaxyl, etc. In particular, it was disclosed that polyoxyethylene alkyl ethers selectively enhance the efficacy of the penetrative fungicide, benzyl triazolyl cyclopentanes (see U.S. Pat. No. 5,393,770).
Accordingly, in order to enhance the fungicidal activity of ethaboxam and to reduce the quantity thereof which needs to be applied, screening of an environment friendly adjuvant and development of a novel fungicidal composition using the same may provide many advantages in both commercial and environmental aspects.
In order to develop a compound enhancing the efficacy of ethaboxam and reducing its quantity which needs to be applied, the present inventors incorporated various potential compounds including anionic and nonionic surfactants into ethaboxarnp. and conducted experiments for their efficacy enhancement activity. As a result, they found that nonionic surfactants of polyoxyalkylene alkyl ether class cause enhancement of activity. Thus, they prepared a one-pack formulation containing them, and found that such formulation remarkably enhances the fungicidal activity at a given level of ethaboxam. Further, they found that the formulation containing a particular polyoxyalkylene alkyl ether has equivalent or superior efficacy evenat a half or less level of ethaboxam, as compared with polyoxyalkylene alkyl ether-free ethaboxam formulation and thus, completed the present invention.
Thus, it is an object of the present invention to provide a fungicidal composition comprising ethaboxam and a non-pesticidal adjuvant which is more cost-effective and readily biodegradable than active ingredients.
A first aspect of the present invention provides a fungicidal composition which comprises N-(xcex1-cyano-2-thenyl)-4ethyl-2-(ethylamino)-5-thiazolecarboxamide of the formula: 
(hereinafter, referred to as ethaboxam) and a nonionic surfactant.
A further aspect of the present invention provides a method for enhancing the activity of ethaboxam, which comprises adding a nonionic surfactant to ethaboxam formulation.
A still further aspect of the present invention provides a method for controlling undesired phytopathogens which comprises applying a formulation prepared from the composition of the present invention to target plants.
The nonionic surfactant which can be employed in the present invention is classified into polyoxyalkylene alkyl ether having polyoxyalkylene as the hydrophilic moiety and aliphatic alcohol as the lipophilic moiety. Preferred polyoxyalkylene alkyl ether is derived from saturated or unsaturated alcohol having the alkyl chain of 12 to 18 carbon atoms or mixtures thereof More preferred polyoxyalkylene alkyl ether is derived from lauryl alcohol having 12 carbon atoms, cetyl alcohol having 16 carbon atoms, stearyl alcohol being saturated and having 18 carbon atoms or oleyl alcohol being unsaturated and having 18 carbon atoms. In the present invention, polyoxyethylene is representative polyoxyalkylene, but polyoxyethylene-polyoxypropylene copolymer wherein ethylene oxide and propylene oxide is copolymerized is also included. For example, polyoxyethylene has an average of 3 to 50, more preferably, 7 to 20, most preferably, 10 to 14 ethylene oxide units per molecule, depending upon the number of carbon atoms in the alkyl chain derived from aliphatic alcohol. In the present invention, particularly preferred is polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether or polyoxyethylene oleyl ether, each of which has an average of 7 to 20 ethylene oxide units per molecule. Polyoxyalkylene alkyl ether employed in the present invention may be obtained by copolymerization of ethylene oxide and natural or synthetic aliphatic alcohol having 12 to 18 carbon atoms and the purity of 50 to 98%.
The fungicidal composition of the present invention contains 1 to 80 wt %, preferably, 5 to 50 wt % of ethaboxam, 10 to 50 wt % of adjuvant, 10 to 89 wt/% of solid or liquid carrier or additive and 0 to 20 wt %, preferably, 0.1 to 10 wt % of surfactants. In case where the composition contains less than 1 wt % of ethaboxam, it is difficult to control the dilution fold. By contrast, in case where the composition contains more than 80 wt % of ethaboxam, it is difficult to maintain physical properties of formulations.
In the composition of the present invention, the presence of polyoxyalkylene alkyl ether reduces the quantity of ethaboxam which needs to be applied to obtain a given level of activity to a significant extent. Practically, a concentration of ethaboxam in a spray for controlling downy mildew is approximately 250 mg/l. But, in case of containing 100 to 2000 mg/l of a particular polyoxyalkylene alkyl ether in a premixed oiie-pack or tank-mixed formulation, even at a half or less concentration of ethaboxam, the efficacy is equivalent or superior to that of the polyoxyalkylene alkyl ether-free formulation.
In the composition for one-pack formulation, an adjuvant is comprised at 10 to 50% by weight. Enhancement of activity can be obtained not only in a one-pack formulation but also in a tank-mixed formulation. But, the concentration of the adjuvant is not fixed in the tank-mixed formulation, differently in the one-pack formulation. It is suggested that enhancement of the activity by addition of adjuvant results from the increase of the permeability into plants by improvement of foliar penetration. This can be inferred from the differences in permeability according to the concentration of adjuvant.
In the present invention, a weight ratio of ethaboxam to adjuvant ranges from about 1:0.5 to about 1:10, preferably, from about 1:1 to about 1:5.
The fungicidal composition in accordance with the present invention is effective for preventing or curing plant diseases caused by phytopathogens as follows: gerbera phytophthora root rot (Phytophthora cryptogea), potato late blight (Phytophthora infestans), hot pepper phytophthora blight (Phytopthora capsici), tomato late blight (Phytophtliora infestans), tobacco black shank (Phytophthora nicotianae var. nicotianae), sesame rot (Phytophthora nicotianae var. parasitica), apple phytophthora fruit rot (Phytophthora cactorum), Cucumis melo L. var. makuzwa MAKINO downy mildew (Pseudoperonospora cubensis), melon downy mildew (Pseudoperonospora cubensis), cucumber downy mildew (Pseudoperonospora cubensis), cabbage downy mildew (Peronospora parasitica), lettuce downy mildew (Bremia lactucae), rose downy mildew (Peronospora sparsa), grape downy mildew (Plasmopara viticola), hop downy mildew (Pseudoperospora humuli) and turf grass Pythium blight (Phythium spp.)
If desired, the fungicidal composition of the present invention contains carriers, surfactants or co-formulants conveniently used in the pesticide formulation area. For example, the composition is processed to unreformed forms, for example, to formulations such as wettable powder prepared by homogeneously mixing active ingredient with extender (e.g. solvent, solid carriers and if appropriate, surfactants) and/or grinding the mixture, dispersible concentrate, emulsifiable concentrate, water dispersible granule, suspension concentrate, oil flowable, etc. and applied by spraying onto foliage and stems of plants. Application frequency and application rate are varied depending on biological properties of pathogens and weather environment. Suitable carrier and additive may be solid or liquid which is generally used in the pesticide formulation, for example, natural or synthetic inorganic materials, solvent, dispersing agents, wetting agents, diluents and the like. Employable solvent is polar solvent such as N-methyl-2-pyrrolidone, dimethyl sulfoxide or dimethyl fornamide. Auxiliary solvent is long-chain alcohol such as N-octyl-2-pyrrolidone, substituted naphthalene, xylene, substituted benzene, decyl alcohol, dodecyl alcohol, etc. and long-chain ester compounds. Employable solid carrier is micronized natural mineral such as talc, kaolin, calcium carbonate, diatomite or pyrophyllite. Moreover, to improve physical properties, particularly wettability, of formulation, a water-soluble ionic compound such as anhydrous sodium sulfate or hydrophilic porous synthetic compound may be employed.
An adjuvant may be adsorbed with an adsorbent such as high-dispersible synthetic silica or high-dispersible adsorbing polymer, etc. (e.g. white carbon, synthetic calcium silicate) within the range of having no harmful effects on storage stability, particularly, at a weight ratio of the adjuvant to the adsorbent ranging from 2:1 to 1:1. Surfactants having various properties may be used depending upon the type of ethaboxam formulations, but suitable is nonionic or anionic surfactant having good wettability and dispersibility. As used herein, surfactants include mixtures thereof A wetting agent employable in the present invention includes anionic wetting agent such as sodium lauryl sulfate, polyoxyalkylene alkyl phenyl ether sulfonate, dialkyl sulfosuccinate, dialkyl naphthalene sulfonate, polyoxyalkylene alkyl ether sulfate, etc., nonionic wetting agent such as acetylene classes and urea complex of non-ionic surfactant. More preferred is sodium lauryl sulfate, polyoxyalkylene alkyl phenyl ether sulfonate, polyoxyalkylene alkyl ether sulfate or urea complex of nonionic surfactant, etc.
In powder formulations, dispersing agent includes anionic dispersing agent such as lignin sulfonate, naphthalene sulfonate, lauryl sulfate, lauryl sulfonate, polyoxyalkylene alkyl aryl ether sulfate, polyoxyalkylene alkyl ether sulfate, etc. and nonionic dispersing agent such as polyoxyalkylene alkyl aryl ether, polyoxyalkylene alkyl ether, etc. However, in case of using polyoxyethylene cetyl ether or polyoxyethylene stearyl ether with an average of 10 or more ethylene oxide units per molecule as adjuvant, additional dispersing agent may not be comprised because the adjuvant may also function as the dispersing agent. In liquid formulations, dispersing agent such as nonionic dispersing agent with a high dispersibility, for example, polyoxyalkylene alkyl aryl ether, preferably, polyoxyalkylene tristyryl phenol ether or polyoxyalkylene alkyl ether, etc. may be used. In many cases, such dispersing agent is also useful as wetting agent. Wetting and dispersing agents are not limited to those as mentioned above, and may be selected among suitable nonionic or anionic surfactants.
The fungicidal composition of the present invention may be manufactured into premixed one-pack formulations by mixing ethaboxam and adjuvant with carrier or surfactant or tank-mixed formulations. In this case, the concentrations of ethaboxam and adjuvant are adjusted to about 30 to about 300 mg/l and about 100 to 2000 mg/l, respectively.
The composition according to the present invention may further comprise one or more additional agents for preventing or curing plant diseases, which include, but are not limited to, azoxystrobin, copper oxychloride, cymoxanil, dimethomorph, famoxadone, fluazinam, metalaxyl, oxadixyl, chlorothalonil, dithianon, folfet, mancozeb, propineb, etc.
In the present invention, wettable powder may be prepared by the following procedure: ethaboxam is mixed with co-formulants other than adjuvant and absorbent and the mixture is ground using a suitable mill. Adjuvant is previously adsorbed to adsorbent such as white carbon, etc. and ground by Warning blender. Then, the two ground parts are homogeneously mixed to obtain the fungicidal composition. On the other hand, dispersible concentrate may be prepared by the following procedure: active ingredient, adjuvant and other co-formulants are dissolved using a suitable mixer to obtain the homogenous combination.